In the related art, water purification equipment such as a water purifier usually adopts a water purifying system constituted by a filter cartridge of multiple stages with a single function for each stage, in which a PP cotton (i.e. an artificial chemical fiber made of polyester fiber), an activated carbon and the like serve as a pre-filter cartridge, RO membrane (RO is an abbreviation of reverse osmosis, and RO membrane is a reverse osmosis membrane, a pore size of which is as small as a nanometer level. Under a certain pressure, water molecules can pass through the RO membrane, but inorganic salts, heavy metal ions, organic matters, colloids, bacteria, viruses and other impurities cannot pass through the RO membrane, so that pure water able to pass and waste water unable to pass are strictly separated) is connected in series, and a post activated carbon is provided, so as to purify and treat the water. However, the whole water purifying system has complicated pipelines and a large outline demission, which is inconvenient for mounting and changing parts and components, and has a high risk of water leakage when a plurality of joints are used for connection. More importantly, service lives of filtering materials in the multi-stage filter cartridge are inconsistent, for example, the service life of the PP cotton is 3 months, the service life of the activated carbon is 6 months, and the service of the RO membrane is 24 months, such that a user needs to replace 3 to 5 stages of the filter cartridge. In addition, the replacement time is difficult to master and a professional installer is required for changing the filter cartridge, thus causing bad user experience and a high comprehensive cost.
Moreover, the water purifier in the prior art mainly has small flux, and thus has the following disadvantages: (1) the water in a pressure tank cannot be discharged completely, and if the water purifier is idle for a long term, the water in the pressure tank contacts a rubber gasbag, and will go bad and produce odor; (2) the water yield is limited, when a large quantity of water is required and the water in the pressure tank runs out, it is necessary to stop using the water purification equipment for a period of time and re-fill the pressure tank to ensure a large yield of water; (3) the pressure tank is outside the water purifier and occupies more kitchen space.